Local and regional diversity in some Aegean land snail faunas

Land snail faunas from maquis and phrygana sites on the islands of Naxos and Crate, and from the eastern Peloponnese were sampled to determine the relationships between local (site) and regional diversities. Mean site diversities are similar in each region. In both the Peloponnese and Crete, however, these represent a much lower proportion of total diversity than is the case for forest faunas from more northerly parts of Europe. The small island of Naxos has more uniform faunas. Some of this between-site diversity is a product of habitat heterogeneity, but most is a product of small-scale biogeographical differentiation. Despite the short (c. 250km) distances between regions, the faunas of each region differ far more than do faunas from forests in northern Europe spread over much greater distances. Nearly 80% of species recorded were found in only one region. These results are compared with those from elsewhere, and discussed in the context of the high diversity of snail faunas in the mediterranean area generally.